Arthritis research & therapy
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Arthritis Res. Ther. · Jan 2006
Genetic mechanisms of knee osteoarthritis: a population-based longitudinal study.
To describe the differences in knee structure and non-knee structural factors between offspring having at least one parent with a total knee replacement for severe primary knee osteoarthritis and age- and sex-matched controls with no family history of knee osteoarthritis, a population-based longitudinal study of 163 matched pairs (mean age 45 years, range 26 to 61) was performed at baseline and about 2 years later. Knee cartilage defect score (0 to 4), cartilage volume and bone size were determined with T1-weighted fat saturation magnetic resonance imaging. Body mass index (BMI), lower-limb muscle strength, knee pain, physical work capacity at 170 beats/minute (PWC170) and radiographic osteoarthritis were measured by standard protocols. ⋯ There were no significant differences in change in BMI, lower-limb muscle strength, knee pain or tibial bone area between these two groups; however, the differences in knee cartilage loss and cartilage defect change decreased in magnitude and became non-significant after adjustment for baseline cartilage volume, tibial bone area, BMI and knee pain. This longitudinal study suggests that knee cartilage loss, change in cartilage defects and decrease in physical fitness all have roles in the development of knee osteoarthritis, which is most probably polygenic but may reflect a shared environment. Importantly, the cartilage changes are largely dependent on baseline differences in cartilage volume, tibial bone area, BMI and knee pain, suggesting that these factors might have a role in their initiation.
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Arthritis Res. Ther. · Jan 2006
Heterogeneity of psychophysiological stress responses in fibromyalgia syndrome patients.
Dysregulated psychophysiological responses have been observed in patients with fibromyalgia syndrome (FMS), although the results are inconsistent. Surface electromyographic (EMG), systolic and diastolic blood pressure, heart rate (HR), and skin conductance levels (SCLs) were continuously recorded at baseline, and during a series of stress and relaxation tasks in 90 FMS patients and 30 age and sex matched healthy controls (HCs). The patient sample demonstrated lower baseline EMG levels compared to the HCs on all tasks. ⋯ A cluster analysis identified four psychophysiological response patterns: 63.3% of HCs showed increased muscle tension and stable cardiovascular responses; 34.8% of FMS patients showed a pattern of increased sympathetic vasomotor reactivity with stable sudomotor and reduced muscular response; 12.2% of FMS patients showed a pattern of increased sympathetic sudomotor reactivity connected with increased sympathetic vasomotor response and reduced muscular response; and, in contrast, 46.7% of FMS patients showed a pattern of parasympathetic vasomotor reactivity and reduced sudomotor as well as muscular response. The identification of low baseline muscle tension in FMS is discrepant with other chronic pain syndromes and suggests that unique psychophysiological features may be associated with FMS. The different psychophysiological response patterns within the patient sample support the heterogeneity of FMS.
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Arthritis Res. Ther. · Jan 2006
Correlation of histopathological findings and magnetic resonance imaging in the spine of patients with ankylosing spondylitis.
Ankylosing spondylitis (AS) is a chronic inflammatory disease which affects primarily the sacroiliac joints and the spine. In patients with active disease, magnetic resonance imaging (MRI) of the spine shows areas of bone marrow edema, the histopathological equivalent of which is unknown. In this study we correlate inflammation in the spine of patients with AS as revealed by histological examination with bone marrow edema as detected by MRI. ⋯ However, in only three of eight patients histopathological inflammation and edema in the zygapophyseal joints correlated with bone marrow edema in zygapophyseal joints of the lumbar spine as detected by MRI. Interestingly, two of these patients showed the highest histological score for bone marrow edema (60%). This first study correlating histopathological changes in the spine of patients with AS with findings in MRI scans suggests that a substantial degree of bone marrow inflammation and edema is necessary to be detected by MRI.
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Arthritis Res. Ther. · Jan 2006
The PI3K-NF-kappaB signal transduction pathway is involved in mediating the anti-inflammatory effect of IB-MECA in adjuvant-induced arthritis.
The anti-inflammatory effect of adenosine was previously found to be mediated via activation of the A3 adenosine receptor (A3AR). The aim of the present study was to decipher the molecular mechanism involved with the inhibitory effect of IB-MECA, an A3AR agonist, on adjuvant-induced arthritis. The adjuvant-induced arthritis rats responded to IB-MECA treatment with a decrease in the clinical score and the pathological score of the disease. ⋯ IB-MECA, an orally bioavailable molecule, activates the A3AR, inducing receptor downregulation and the initiation of a molecular mechanism that involves de-regulation of the PI3K-NF-kappaB signaling pathway. As a result, a potent anti-inflammatory effect manifested in the improvement of the disease clinical score and pathological score occurs. The finding that the A3AR expression level in the peripheral blood mononuclear cells and in the DLN reflects the receptor status in the remote inflammatory site suggests use of the A3AR as a follow-up biomarker.